Patent US3061398A successfully refreshed from Google Patents.
Patent US3648656A successfully refreshed from Google Patents.
US3648656A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dry developer for an electrostatic image developing apparatus
Assignee: Minolta Co Ltd
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Filing: 1970-07-07
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Granted: 1972-03-14
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Expires: 1990-07-07
Abstract
Abstract The present invention relates to a dry developer apparatus for forming a magnetic brush in electrostatic image development, wherein the developer composed of a magnetic carrier and toner magnetically adheres to a rotary roller having a specific magnetic pole. The magnetic brush is formed between the rotary roller and an opposed plate of different magnetic polarity which is mounted in parallel spaced relationship to the rotary roller by a control permanent magnet mounted in parallel spaced relationship to the roller. Rotation of the permanent magnet so that a magnetic polarity opposite to that of the roller causes the developer to be attracted to the roller surface.
Inventors
- 👤 Masaya Ogawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 21:30
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/08; G03G15/09
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
140 words
A dry developing apparatus for electrostatic images, comprising: a developer composed of a magnetic carrier and toner, a reservoir for retaining said developer, a magnetic roller supported rotatably on said reservoir, a stationary magnetic plate mounted in parallel opposed spaced relationship to said roller, magnets interposed between the ends of said rotary roller and said opposed plate to magnetize said roller and said plate to opposite polarities, a control permanent magnet mounted rotatably to the outer side wall of said reservoir and parallel to said rotary roller, said control permanent magnet controlling the attraction of said developer onto said roller wherein developer is formed on said roller with said control magnet positioned to have a different polarity than said roller and repulsing said developer from said roller with said permanent magnet positioned to have the same polarity as said roller.
Claim 2
Dependent Claim
140 words
A dry developing apparatus for electrostatic images, comprising: a developer composed of a magnetic carrier and toner, a reservoir for retaining said developer, a magnetic roller supported rotatably on said reservoir, a stationary magnetic plate mounted in parallel opposed spaced relationship to said roller, magnets interposed between the ends of said rotary roller and said opposed plate to magnetize said roller and said plate to opposite polarities, a control permanent magnet mounted rotatably to the outer side wall of said reservoir and parallel to said rotary roller, said control permanent magnet controlling the attraction of said developer onto said roller wherein developer is formed on said roller with said control magnet positioned to have a different polarity than said roller and repulsing said developer from said roller with said permanent magnet positioned to have the same polarity as said roller.
Claim 3
Dependent Claim
38 words
A dry developing apparatus as in claim 1, wherein said rotary roller has a tubular surface with smooth surface portions at each end adjacent said reservoir and a roughened surface between said end portions for retaining developer thereon.
Claim 4
Dependent Claim
42 words
A dry developing apparatus as in claim 1, wherein said developer reservoir includes a pulsator mounted by a shaft parallel to said rotary roller and at a lower elevation within said reservoir to rotate in the opposite direction to said rotary roller.
Claim 5
Dependent Claim
133 words
A dry developing apparatus, comprising: a developer of a magnetic carrier and toner, a reservoir for retaining said developer, a magnetic roller supported rotatably on said reservoir, a stationary magnetic plate mounted in parallel opposed spaced relationship to said roller, magnets interposed between said rotary roller and said opposed plate to magnetize each member to a different polarity respectively, a shaft mounted parallel to said rotary roller on the outer side wall of said reservoir, a plurality of control permanent magnetic elements each mounted rotatably on said shaft for controlling the formation of a magnetic brush on said rotary roller whereby said developer is attracted to or repulsed from desired portions of said magnetic roller with said permanent magnetic elements selectively positioned to have the same or different polarity as said magnetic roller.
Claim 6
Dependent Claim
133 words
A dry developing apparatus, comprising: a developer of a magnetic carrier and toner, a reservoir for retaining said developer, a magnetic roller supported rotatably on said reservoir, a stationary magnetic plate mounted in parallel opposed spaced relationship to said roller, magnets interposed between said rotary roller and said opposed plate to magnetize each member to a different polarity respectively, a shaft mounted parallel to said rotary roller on the outer side wall of said reservoir, a plurality of control permanent magnetic elements each mounted rotatably on said shaft for controlling the formation of a magnetic brush on said rotary roller whereby said developer is attracted to or repulsed from desired portions of said magnetic roller with said permanent magnetic elements selectively positioned to have the same or different polarity as said magnetic roller.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-03-14 | 1975-09-13 | 1976-03-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-03-14 | 1979-09-13 | 1980-03-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-03-14 | 1983-09-13 | 1984-03-14 | $7700.00 | Window Closed / Lapsed |